What ecm should I start with?

I have a 94 suburban K1500 5.7 that has had a 5sp swapped in. It has had some perf upgrades done to it(intake,cam,headers,exh).
It still has the original ecm in it which is a 395, BJLF. What I would like to do is find a complete ecm that would be the best possible fit for the MT setup it has now. I understand that I will need to aquire equipment and log/tune to get everything dialed in eventualy, but for right now I cant figure out what I need. Shouldnt I try to find an ecm from a 5.7 4wd MT truck? Wouldnt that be the closest match to what I have? I believe I should pick up a better suited ecm, have it in the burb, then find an ecm thats best suitable for the tuning aspect to play around with. Then if/when something screws up I can swap back the other ecm. Does this make sense?
I am also confused about what ecm's have what features. 395 vs 396 vs 427 vs 747 etc. What are the differences? Which is the best platform to build on?

I apreciate any advice on what to do.
Thanks

The 6395 should work just fine. GM did not use those PCM's with a manual trans and a 5.7 engine. You can change the calibration for the PCM you have and convert it to manual trans and also tune for the bolt-ons that have been installed.
You will need something like this: http://www.moates.net/g1-memory-adap....html?cPath=64
A couple of flash chips like this: http://www.moates.net/c2-sst-27sf512....html?cPath=26
Moates has a package deal with two chips and the adapter.

You will need to be able to program the chips with something like this: http://www.moates.net/burn2-chip-pro....html?cPath=94

A cable to datalog with: http://www.moates.net/aldu1-and-cabl....html?cPath=97

There is less expensive equipment out there and some you can build yourself.

Download Tunerpro RT and load up your bin and xdf from here and start looking at what is involved:
http://www.gearhead-efi.com/Fuel-Inj...Information-0D